Methods for approximation and fastening of soft tissue

ABSTRACT

Methods for approximating and fastening tissue by application of one or more tissue fasteners are provided. In one embodiment, spaced apart tissue locations are engaged by tissue penetrating members of a deformable fastener, one of more of the engaged tissue locations is moved toward another engaged tissue location to approximate the spaced apart locations, and the deformable fastener is deployed to secure the approximated tissue locations. These methods may be used in laparoscopic plication gastroplasty procedures for forming an invaginated tissue fold, to close holes in the gastrointestinal lumen, and in a variety of interventional procedures.

REFERENCE TO PRIORITY APPLICATIONS

This application claims priority to U.S. International PatentApplication No. PCT/US2008/56921 filed Mar. 13, 2008 and is acontinuation-in-part of U.S. patent application Ser. No. 12/048,206,filed Mar. 13, 2008 and issued as U.S. Pat. No. 8.142.450 on Mar. 27,2012, which claims priority to U.S. Provisional Patent Application No.60/894,626 filed Mar. 13, 2007. This application also claims priorityunder 35 U.S.C. §119(e) to U.S. Provisional Patent Application No.61/031,124 filed Feb. 25, 2008. These patent applications areincorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates generally to methods and devices forapproximating and fastening of soft tissues within the body. Uses forthe methods and devices of the present invention include laparoscopicand endoscopic interventions involving reconfiguration or repair of softtissues, such as reconfiguration or repair of gastrointestinal tissuesor other soft tissues within the abdominal cavity.

BACKGROUND AND DESCRIPTION OF THE PRIOR ART

The use of devices for tissue approximation and fastening is well knownin the art. For example during an open abdominal interventionalprocedure, an incision is made through the abdominal wall to gain accessto the peritoneal cavity. When the surgeon has corrected the abdominaldefect, the peritoneum, abdominal muscles, fascial layers and skin mustbe approximated and fastened to complete the closure of the abdominalcavity. During various interventional procedures a surgical openingcreated in the stomach must be approximated and fastened closed to allowfor the healing process to complete and to prevent stomach contents fromentering the peritoneal cavity. In each case the success of the repairand ultimate healing process is highly dependent on the technique andskill of the surgeon. The process of approximating the individual layersof tissue and fastening them securely is tedious and time consuming.

Tissue approximation and fastening is well known throughout history.Suturing materials have been commonly used to aid approximation oftissue for the appropriate duration of the healing process. For example,U.S. Pat. No. 2,808,055 describes a device for surgical stitching thatprovides an integrated suture dispenser and feeding mechanism to enhancethe surgeon's ability to apply sutures quickly and effectively. U.S.Pat. No. 4,165,747 describes methods of both approximating and fasteningtissue as it is being held. Further exemplary prior art is disclosed inU.S. Pat. Nos. 5,565,004, 5,643,295 and 5,972,021. The disadvantages andlimitations of the methods used in these devices include relativelylarge skin incisions and resultant scars from providing the surgeonaccess to the abdominal cavity. Extended time under anesthesia due tothe time consuming nature of suturing the wound closed, and lengthyrecovery times for patients who undergo these invasive proceduresresulting in high costs. These are significant drawbacks for this typeof intervention.

Advances in devices for minimally invasive interventions led tocombining functionality of approximating and fastening tissuessimultaneously. Exemplary prior art is disclosed in U.S. Pat. Nos.5,332,142, 5,485,952, 5,662,258, 5,700,275 and 6,986,451.

These devices greatly reduced the dependence on the surgeons suturingtechnique by replacing the suture with surgical staples, furthermore,the mechanically fired staples greatly reduced the time necessary toapproximate and fasten tissue thereby shortening the time a patient waskept under anesthesia. Additionally the use of these devices throughsmall incisions in the skin reduced the time required for the patient torecover from surgery. However these devices are complicated tomanufacture, expensive and typically require the tissue being fastenedmust also be transected. Additionally the approximation possible withthese types of devices is limited by the size of the aperture of theopen jaws of the instrument, often being less than the outside diameterof the instrument shaft itself. Another disadvantage of these devicesoccurs when the tissue to be fastened does not completely fill thestapler jaws; staples not in contact with tissue fall loosely into thepatient's abdomen. These are significant disadvantages for this type ofdevice.

While laparoscopic stapling devices have in many cases improved thespeed of interventional procedures and reduced the dependence on anindividual's technique to guarantee consistent outcomes, manyinterventional procedures still require the flexibility offered to thesurgeon of needle and thread. Devices like the Autosuture Endo Stitch™as described in U.S. Pat. No. 5,480,406, provides a device to facilitatesuturing laparoscopically. While tedious, time consuming, and techniquesensitive, laparoscopic suturing is a method used for fastening tissuesto this day. Minimally invasive interventional procedures that usesuture in spite of the many disadvantages noted, represent anopportunity for device innovation and improvement when, as in thepresent invention, these disadvantages can be overcome.

More recently, sophisticated endoscopic devices like U.S. Pat.Application No. 2004/0215216 to Gannoe discloses a tissue approximationand fixation device. The device is used to approximate two folds of softtissue to form a pleat to be used for gastric reduction surgery or GERDtreatment procedures. In this disclosure, the device fixates portions oftissue together so that the tissue can fuse or scar over, however Gannoespecifically discusses the need to apply a clamping force that does notclamp too tightly, thus leading to complications such as pressurenecrosis, or too lightly, which may result in an incomplete tissueunion. Thus, inconsistent securement is a problem that requires preciseapplication of force. The present invention, as will be shown, providesthe appropriate clamping force without the need for precise adjustmentof clamping force by the surgeon.

Considering the technical limitations and shortcomings associated withthe various methods utilized in prior art to approximate and fastentissue, as described above, it is apparent that surgeons and patientscould benefit from a minimally invasive device that approximates tissuesand delivers fasteners in a faster, safer and more consistent manner,thereby providing the surgeon with greater control and flexibility toperform new beneficial interventional procedures.

BRIEF SUMMARY OF THE INVENTION

In general, the devices of the present invention are handheldinterventional instruments having a proximal handle assembly, anelongate shaft assembly, and a distal tool assembly. The handle assemblyis used to manipulate and position the device, and is further configuredwith one or more actuation mechanisms that allow the surgeon to controlthe tissue approximation and fastening functions of the device. Theelongate shaft assembly consists of one or more tubular components andprovides mechanisms for operatively connecting the actuation mechanismswithin the proximal handle assembly to the distal tool assembly. Thesedevices may be configured for use in open, laparoscopic or endoscopicprocedures; accordingly, the elongate shaft assembly may be rigid,flexible, articulating, and combinations thereof, and may be rotatablerelative to the orientation of the proximal handle assembly.

The distal tool assembly includes mechanisms for engaging tissue at twoor more spaced-apart tissue locations on a tissue surface, and isfurther configured to allow the operator to reposition and/or move atleast one of the spaced-apart tissue locations toward anotherspaced-apart tissue location thereby approximating the engaged tissuelocations near the distal end of the device. In certain embodiments, thedevice may be designed and configured to allow the tissue engagement attwo or more locations to be performed sequentially, whereas in otherembodiments the device may be designed and configured to the allowtissue engagement at two or more locations to be performedsimultaneously. A wide variety of tissue engagement mechanisms arepossible within the scope of the present invention, including needles,hooks, barbs, clamps, grippers, forceps, jaws, teeth, vacuum ports, andthe like. In certain embodiments, the distal tool assembly furtherincorporates mechanisms for deploying one or more individual tissuefasteners into the approximated tissue, to securely hold the tissue inthe approximated configuration after the device is removed from thetreatment site. A wide variety of fasteners may be used within the scopeof the present invention, including sutures, staples, screws, tacks,clips, hooks, clamps, rivets, t-tags, expandable anchors, and the like.The devices may be configured to deliver a single fastener, requiringreloading after each tissue engagement, approximation and fasteningcycle, or alternatively, in other embodiments, the device may beconfigured as a multi-fire instrument in which a plurality of fastenersare pre-loaded into the device, allowing successive tissue engagement,approximation and fastening cycles to be completed without reloading orremoving the device from the patient. In some embodiments the device isconfigured having separate and independently operable tissueapproximation and fastening mechanisms, whereas in other embodimentsmulti-functional components provided within the distal tool assembly aredesigned and configured to provide both the tissue approximation andfastening functions. This can simplify the mechanisms required, loweringcost and increasing reliability, as well as reducing the device profile.

A variety of configurations for the distal tool assembly are possiblewithin the scope of the present invention. For use in minimally invasivelaparoscopic and endoscopic procedures, it is generally desirable thatthe device be provided in an initial collapsed (i.e. pre-deployed)configuration for insertion into the patient, and that after insertion,upon actuation by the user, the device is reconfigured to an expanded(i.e. deployed) configuration. In the deployed configuration, the tissueengagement mechanisms are exposed and positioned appropriately to allowtissue to be contacted and engaged at two or more locations. In certainembodiments, one or more of the tissue engagement mechanisms may beattached to, or fixedly positioned with respect to, the distal end ofthe device. In other embodiments, separately or in combination with theabove, one or more of the tissue engagement mechanisms may also beattached to, or fixedly positioned with respect to, one or more moveablemembers configured as part of the distal tool assembly. In the lattercase, during use the moveable members are capable of being actuatinglycontrolled by the operator (e.g. remotely, from the handle assembly)such that the tissue engagement mechanism may be repositioned from alocation near the distal end of the device to a location away from thedistal end of the device in order to engage tissue, after which themotion may be reversed to return the tissue engagement mechanisms, withengaged tissue attached thereto, to a position in proximity to thedistal end of the device.

Within the scope of the present invention, movement of the engagedtissue locations toward one another to approximate the tissues can occurby manual repositioning of the distal tool assembly, by actuatedmovement of one or more moveable members incorporated within the distaltool assembly, and by combinations of the foregoing. After the tissuesare approximated near the distal end of the device, one or morefasteners may be deployed from the device to securely hold the tissuesin the approximated configuration. In some embodiments, at least aportion of one or more of the tissue engagement mechanisms and/ormoveable members are designed to be brought together, joined, mated, orotherwise firmly held in close proximity to one another as an assembly,which is then releasably detached from the device after the tissues havebeen approximated, being left implanted in the tissue and therebyserving as the tissue fastener to securely hold the tissues in theapproximated configuration.

In one embodiment, for example, the distal tool assembly in the deployedconfiguration provides two or more exposed tissue engagement mechanisms,each of which is fixedly positioned with respect to the distal end ofthe device, such that in operation, the surgeon first moves the distalend of the device to a first location to engage tissue with a firsttissue engagement mechanism, then moves the device to a second locationto engage tissue with a second tissue engagement mechanism, dragging thefirst engaged tissue location to the second, and thereby approximatingthe engaged tissue locations. In another related embodiment, the twoexposed tissue engagement mechanisms are configured as opposite sides ofa releasable tissue fastener (e.g. opposing legs of a deformablebox-type staple) that is initially at least partially deployed to afirst, open configuration, while being firmly held in position near thedistal end of the device. After the tissues have been approximated inthe manner described, the fastener is actuatingly reconfigured to asecond, closed configuration, and then releasably deployed from thedevice to securely hold the tissue in the approximated configuration.

In another embodiment, for example, there may be a first tissueengagement mechanism positioned fixedly with respect to the position ofthe distal end of the device, while a second tissue engagement mechanismmay be positioned at the distal end of a moveable member that can berepositioned such that its distal end extends away from the device. Themoveable member can be rigid, flexible, articulating, and combinationsof the foregoing, and the proximal end of said moveable member may beattached to the device using a pivot connection, hinge connection,flexible connection, tether, and the like. In operation, the distal endof the device (having a first tissue engagement mechanism fixedlypositioned near its distal end) is used to engage tissue at a firstlocation, while the moveable member (having a second tissue engagementmechanism fixedly positioned near its distal end) engages tissue at asecond location. The order in which said engagement is performed isoptional and may be determined primarily by convenience. Upon actuatedretraction of the moveable member, the second engaged tissue location isdrawn in toward the distal end of the device and thereby approximatedadjacent the first engaged tissue location that is positioned near thedistal end of the device.

In other embodiments, two or more such moveable members are provided,each having an associated tissue engagement mechanism positioned nearits distal end. In this example, the step of engaging tissue at twolocations occurs after initially deploying the distal end of saidmoveable members away from the longitudinal axis of the device. Uponactuated retraction of said moveable members, the engaged tissuelocations are both moved toward to the longitudinal axis of the device,being moved toward one another and approximated near the distal end ofthe device. Some advantages of this type of device configuration overthe previously described embodiments are that the distal end of thedevice itself need not become attached to the target tissue, nor does itneed to be significantly repositioned to effect the approximation. Thisresults in greater freedom and ease of use for the surgeon, and lessvariation in the tissue reconfiguration which may be attributable tosurgeon technique. As described previously, once the tissues have beenapproximated near the distal end of the device in this manner, thefastener may be deployed to securely hold tissues in the approximatedconfiguration after the device has been removed from the treatment site.

In another embodiment, one or more tissue engagement mechanisms may beprovided at the distal end of one or more moveable members consisting ofa releasable flexible tether (e.g. suture, wire, cable, or the like)that is initially retracted and held within the elongate shaft assembly.In this example, the distal end of the device is positioned to engagetissue at a first location, and the flexible tether is released andextended as the distal end of the device is moved freely away, e.g. toengage tissue at a second tissue engagement location. The proximal endof the flexible tether remains connected to the device, much like adropped anchor remains connected to a ship. In this manner, the flexibletether may later be pulled or retracted back into the shaft of thedevice, or alternatively a cinching member through which two or moresuch deployable flexible tethers pass may be slid distally down thelength of tethers, thereby pulling on and approximating the engagedtissue locations. Devices of this nature may include tissue engagementmechanisms designed to partially and/or releasably engage the tissuesurface (e.g. hooks, clamps, grippers, forceps, jaws, teeth, vacuumports, and the like), or alternatively, the tissue engagement mechanismsmay be designed to fully penetrate through and/or otherwise remainimplanted in the tissue (e.g. t-tags, expandable anchors, and the like).These devices may be designed and configured to deploy a singlereleasable flexible anchor/tether pair, in which case the device must beremoved from the patient and reloaded for successive cycles.Alternatively, the device may be configured as a multi-fire instrumenthaving more than one set (i.e. multiple pairs) of releasable flexibleanchor/tethers that are pre-loaded into the device and sequentiallyadvanced during operation. In this case, the user can perform aconsecutive series of tissue engagement, approximation and fasteningsteps without reloading or removing the device from the patient.

While the present invention will be described more fully hereinafterwith reference to the accompanying drawings, in which particularembodiments are shown and explained, it is to be understood that personsskilled in the art may modify the embodiments herein described whileachieving the same methods, functions and results. Accordingly, thedescriptions that follow are to be understood as illustrative andexemplary of specific structures, aspects and features within the broadscope of the present invention and not as limiting of such broad scope.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Overview of a tissue approximation device according to oneembodiment of the present invention.

FIG. 2. Close up views of the distal end of a tissue approximationdevice according to one embodiment of the present invention in the (A)pre-deployed configuration, and (B) deployed configuration.

FIG. 3 Close up view of the proximal handle assembly of a tissueapproximation device according to one embodiment of the presentinvention.

FIG. 4. Close up views of the distal end of an endoscopic tissueapproximation device according to one embodiment of the presentinvention, (A) after deployment, tissue engagement and subsequentretraction to approximate tissue thereby creating a tissue fold, and (B)after deployment, tissue engagement and subsequent retraction toapproximate tissue thereby closing a wound or other opening in tissue.

FIG. 5. Close up view of the distal end of an endoscopic tissueapproximation device according to one embodiment of the presentinvention showing articulation and rotation.

FIG. 6. Overview of a system for tissue approximation and fasteningaccording to another embodiment of the present invention.

FIG. 7. Close up views of the distal end of an endoscopic system fortissue approximation and fastening according to another embodiment ofthe present invention (A) pre-deployed, (B) tissue approximated,fastener deployed and device disengaged from tissue.

FIG. 8. Close up views of the distal end of a tissue approximation andfastening device according to another embodiment of the presentinvention, (A) device inserted through hole in tissue, with moveablemembers deployed and tissue hooks positioned to engage the distal tissuesurface, (B) tissue approximated, fastener deployed and devicedisengaged from tissue.

FIG. 9. Close up views of the distal end of an endoscopic system fortissue approximation and fastening according to another embodiment ofthe present invention (A) pre-deployed, (B) moveable arms deployed, (C)tissue approximated and fastener being deployed, and (D) fastenerdeployed and device removed.

FIG. 10. Close up views of the distal end of a tissue approximation andfastening device according to another embodiment of the presentinvention, (A) pre-deployed, (B) inserted through hole in tissue, (C)moveable members deployed and tissue hooks positioned to engage distaltissue surface, (D) moveable members retracted and fastener assemblydeployed.

FIG. 11. Overview of an endoscopic system for tissue approximation andfastening according to another embodiment of the present invention.

FIG. 12. Close up views of the distal end of an endoscopic system fortissue approximation and fastening according to another embodiment ofthe present invention (A) moveable members deployed and tissue engaged,(B) moveable arms being retracted to create a tissue fold, (C) tissueapproximated and fastener assembly deployed, and (D) a plurality offastener assemblies deployed producing a plication in the tissue.

FIG. 13. Overview of a system for tissue approximation and fasteningaccording to another embodiment of the present invention.

FIG. 14. A fastener for use in conjunction with a system for tissueapproximation and fastening according to another embodiment of thepresent invention (A) pre-deployed configuration, and (B) deployedconfiguration.

FIG. 15. Close up view of the distal end of an system for tissueapproximation and fastening according to another embodiment of thepresent invention.

FIG. 16. Close up views of the distal end of a system for tissueapproximation and fastening showing a method of use according to oneembodiment of the present invention (A) device positioned above tissuesurface, (B) tissue engaged at a first location, (C) device repositionedto engaged tissue at a second location, (D) two engaged tissue locationsapproximated near the distal end of the device to create an invaginatedtissue fold, and (E) box-type staple deployed to secure tissue in theapproximated configuration.

DETAILED DESCRIPTION OF THE INVENTION

According to one embodiment of the present invention, illustrated inFIG. 1, tissue approximation device 100 is configured for laparoscopicor endoscopic use, consisting of a proximal handle assembly 105,longitudinal tube assembly 110 and distal tool assembly 115.Longitudinal tube assembly 110 is typically produced from flexiblebiocompatible materials and is configured to be inserted into the bodyvia a laparoscopic access port (e.g. a small incision or trocar) orflexible endoscope. It is preferably between 0.5 mm and 20 mm indiameter, more preferably between 1 mm and 15 mm in diameter, and mostpreferably between 1.5 mm and 10 mm in diameter. It may consist of asingle tube, multiple concentric tubes, and combinations thereof.

FIG. 2 shows close up details of distal tool assembly 115. In thepre-deployed configuration (FIG. 2A) two moveable arms 118 areconfigured as individual longitudinal components that are operativelyconnected to the distal end of internal shaft 120. Internal shaft 120 isslidably and rotatingly positioned within the working channel 122 ofouter tube 124, and its motion is actuated from proximal handle assembly105, as will be described below. As shown in FIG. 2A, in thepre-deployed (i.e. fully retracted) position, moveable arms 118 are heldsubstantially within longitudinal tube assembly 110, with only thedistal ends of moveable arms 118 visible near the distal end of device100.

Each of moveable arms 118 is configured at its distal end with arm tip126, wherein each said arm tip 126 includes one or more elements whoseworking function is to controllably, selectively and releasably grasp,grab, grip, pierce, hold or otherwise engage tissue. In the exampleshown, arm tips 126 incorporate sharp tissue hooks 128. A variety ofother configurations and mechanisms are possible within the scope of thepresent invention for engaging tissue at the distal end of moveable arms118. For example, teeth, barbs, jaws, graspers, forceps, clamps, vacuumports, and the like may be used, the choice of which may depend upon thenature of the tissue to be engaged, desired depth of penetration, and soon. In some embodiments, the distal ends of moveable arms 118 (andassociated tissue engagement means, such as 126 and sharpened tissuehooks 128) are completely retracted within longitudinal tube assembly110 in the pre-deployed configuration, such that no portions are exposedthat may possibly cause accidental tissue damage during insertion,positioning and/or removal of the device from the body.

As shown in FIG. 2B, in the deployed configuration moveable arms 118slide distally 130 and thereby extend out of and away from the distalend of longitudinal tube assembly 110. In this manner, arm tips 126become spaced apart by a predetermined distance (that may be optionallyadjusted by the operator), and the orientation of tissue hooks 128 isaltered such that they are placed in a desirable position forsubsequently engaging tissue.

FIG. 3 shows a cross section of proximal handle assembly 105. Fingerrings 140 and thumb ring 142 are provided to allow the user to grasp thedevice. Finger rings 140 are fixedly connected to device body 144whereas thumb ring 142 is fixedly connected to handle shaft 146, whichslides proximally and distally within device body 144 when the positionof thumb ring 142 is moved relative thereto during actuation by theuser. Handle shaft 146 is fixedly connected to internal shaft 120(described previously) such that actuated distal movement of thumb ring142 by the user causes distal tool assembly 115 to reconfigure from itspre-deployed to deployed configuration. After tissue has been engaged,as described previously, upon actuated proximal movement of thumb ring142 by the user causes distal tool assembly to return toward itspre-deployed configuration, thereby approximating the engaged tissuelocations near the distal end of device 100.

Also positioned within proximal handle assembly 105 is rotation knob 150that is fixedly connected to handle shaft 146. Torsion element 148interconnects handle shaft 146 with internal shaft 120, transmitting therotational motion of rotation knob 150 thereto, which provides the useran ability to rotatably adjust the orientation of distal tool assembly115 relative to the position of proximal handle assembly 105.

To illustrate the exemplary use of device 100, FIG. 4 shows close upviews of the distal end of the device when used to approximate tissuefor two different surgical purposes. In both FIG. 4A and FIG. 4B,proximal handle assembly 105 (not shown) of device 100 was previouslyactuated by the user to deploy moveable arms 118 from withinlongitudinal tube assembly 110. Tissue was subsequently engaged at twoseparate and spaced apart locations, 160 and 162, by bringing arm tips126 having tissue hooks 128 into direct contact with the proximalsurface 165 of tissue layer 168. The user then reverse actuated proximalhandle assembly 105 to retract moveable arms 118 back toward theoriginal pre-deployed configuration within longitudinal tube assembly110, which thereby caused engaged tissue locations 160 and 162 to bebrought toward one another and approximated substantially near thedistal end of device 100. As shown in FIG. 4A, said tissue approximationhas been used to create an invaginated tissue fold 170 in tissue layer168 whose proximal surface 165 positioned within said tissue fold 170are in intimate contact 172. As shown in FIG. 4B, said tissueapproximation has been used to bring together and place in intimatecontact opposing edges 180 and 182 of a hole, wound or other type ofopening in tissue layer 168.

FIG. 5 shows a close up view of the distal end of device 100,illustrating means for articulation and rotation of distal tool assembly115, according to one embodiment of the present invention. Positionedwithin longitudinal tube assembly 110 is flexible cable 505 that isconnected at its proximal end to sliding knob 152 (positioned withinproximal handle assembly 105 as shown in FIG. 3) and at its distal endto anchor 510. Anchor 510 is fixedly attached to the interior wall oflongitudinal tube assembly 110. When the user actuates sliding knob 152at proximal handle assembly 105 by moving it in the proximal direction,a tension 515 is applied to flexible cable 505 and transmitted to anchor515, providing a force component having a direction and magnitudesufficient to cause the distal end of device 100 to bend within theplane established by longitudinal axis 520 and flexible cable 505. Theangle of bending 525 is thereby adjustably controlled by the user viathe positioning of sliding knob 152 on proximal handle assembly 105. Asdiscussed previously, when the user turns rotation knob 150 at proximalhandle assembly 105, a rotational force is transmitted via torsionelement 148 to internal shaft 120. This causes rotation of internalshaft 120 within longitudinal tube assembly 110, thereby producingrotation 530 of the plane defined by moveable arms 118 around distallongitudinal axis 535. The angle of rotation 530 is thereby adjustablycontrolled by the user via the positioning of rotation knob 150 onproximal handle assembly 105.

It is also possible within the scope of the present invention toincorporate into the device more than one flexible cable, as describedabove. In such cases, by positioning the more than one said flexiblecables on opposing and/or orthogonal sides of the longitudinal tubeassembly, it is possible to bend the longitudinal tube assembly in morethan one direction. Accordingly, the rotational and articulationcapabilities that are optionally incorporated into devices of thepresent invention, as described herein, are important for providing thesurgeon the ability to guide, steer, arrange, or otherwise control inthree dimensions the position and orientation of the distal portion ofthe device relative to the target tissue surface in order to placedistal tool assembly 115 into the best possible configuration forsubsequent approximation and fastening, independent of the handleposition or location, orientation, etc., of the body access relative tothe target tissue. It should be recognized that other mechanisms knownto those skilled in the art may be used to provide such rotationaland/or articulation capabilities, and these are considered within thescope of the present invention. For example, pivot joints, flexiblejoints, hinges, u-connectors, and the like, may be incorporated intolongitudinal tube assembly 110 to serve as articulating joints. Itshould also be noted that it is possible to incorporate more than onearticulation mechanism into devices of the present invention in order tofurther enhance the ability to steer, position and orient distal toolassembly 115, where the number of such articulation joints, therespacing and positioning along the length of longitudinal tube assembly110, their permitted angle of bending, etc., are all adjustableparameters that may be optimally designed depending on the needs of themission for a particular interventional procedure. In the case oflaparoscopic devices, for example, at least one such articulation joint,along with rotational capability, are desirable to enable tissueapproximation and fastening to be performed throughout the entireabdominal cavity from a single point of access, e.g. a single trocarplaced through the umbilicus. Such single access port laparoscopicprocedures are becoming increasingly desirable for minimizing scarringand healing time for the patient. Alternatively, in the case ofendoscopic devices inserted into or through the gastrointestinal tract,a higher degree of control may be desirable, which may require the useof several such articulating joints, whose motions may either becontrolled in a coordinated fashion or independently, by using actuatingmechanisms incorporated into proximal handle assembly 105 and operablyconnected to the individual rotational and articulation elements.

The tissue approximating devices of the present invention may furtherincorporate complementary means for fastening, retaining, holding orotherwise securing tissue in order to substantially maintain the tissuein the approximated configuration. Incorporation of such complementaryfastening means typically involves providing within the device one ormore suitable tissue retaining fasteners, along with integratedmechanisms for delivering said fasteners to the approximated tissue.Accordingly, the tissue approximating devices, tissue retainingfasteners and integrated fastener delivery mechanisms of the presentinvention, taken together, comprise systems of the present invention. Itshould be obvious to those skilled in the art that, within the scope ofthe present invention, a variety of suitable tissue retaining fastenersand fastener deployment mechanisms that are well known in the art may beincorporated in these systems for the purpose of anchoring, fastening,holding, attaching, or otherwise securing the approximated tissuesurfaces. Examples of suitable tissue fasteners that may be used tosecure the approximated tissue include but are not limited to sutures,cinches, snares, staples, screws, tacks (e.g. U-shaped, circular andhelical fasteners), clips, hooks, rivets, clamps, t-tags, and the like.

One embodiment of the present invention, illustrated in FIG. 6, involvesa system 600 configured for flexible endoscopic approximating andfastening of tissue. System 600 includes a tissue approximating devicesubstantially similar to that described above (i.e. device 100).Accordingly, proximal handle assembly 605, longitudinal tube assembly610 and distal tool assembly 615 are all similar in design andfunctionality to the previously described embodiment, however,incorporation of the tissue fasteners and integrated fastener deliverymechanisms requires additional components and features. For example,positioned at the intersection between proximal handle assembly 605 andlongitudinal tube assembly 610 is fastener deployment knob 620 which canbe actuated by the user, after tissue has been approximated, in order todeliver the fastener to the tissue, as explained below.

According to one embodiment of the present invention, the distal toolassembly is configured to approximate tissue and then deliver a box-typestaple to secure the tissue in the approximated configuration. FIG. 7Aillustrates details of a multi-functional distal tool assembly 715 inthe collapsed state. In this configuration, located along longitudinalaxis 718 are two (or more) extendible members 720, each beingoperatively connected to actuating mechanisms accessible to an operatorat proximal handle assembly 605. Each of the extendible members 720 isconfigured at its distal end with a distal tip 724, and each distal tip724 incorporates one or more tissue engagement mechanisms whose workingfunction is to controllably and selectively grasp, grab, grip, pierce,hold or otherwise engage tissue. In the example shown, distal tips 724incorporate sharpened tissue hooks 726. Box-type staples in pre-deployedstate 730 are stored inside the device and are configured (using, forexample, guide channels and a spring loading mechanism well known tothose skilled in the art) to slidably move toward the distal end ofmulti-functional distal tool assembly 715 and into the pre-fire position731 as staples are sequentially ejected from the device. Pistons 732 arepositioned at the distal end of staple forming shaft 733, and, alongwith stationary anvil 734, are used to deform the legs 735 of staple 731and thereby reconfigure and eject the staples when the device isactuated by the user. Typically the entire staple forming assembly isprotected from contacting tissue during device insertion and removal bybeing positioned inside longitudinal tube assembly 610, with only thedistal portions anvil 734 and staple legs 735 exposed prior to deployingthe fastener. Alternatively, it may be desirable to configure the stapleforming assembly to be partially exposed by extending it distally beyondthe end of longitudinal tube assembly 610, or to retract a distalportion of longitudinal tube assembly 610, during actuation. Althoughlinearly slidable pistons 732 are shown in this embodiment, it should berecognized that other mechanical mechanisms known to those skilled inthe art may be used to transmit the actuating mechanical forces tostaple legs 735 to thereby deform and deploy the fastener, for example,cams, levers, gears, and the like may be used.

FIG. 7B shows a deformed staple after ejection, implanted in andsecurely fastening the approximated tissue. In this example, similar tosituation described in FIG. 4B, the device is used to close a hole-typedefect present in tissue layer 740 by engaging and approximating tissueon opposing sides of the hole, for example at locations 742 and 744, andthen deploying fastener 745 to securely maintain the tissue in theapproximated configuration. To accomplish closure of the hole-typedefect in tissue as shown in this example, distal tool assembly 715 wasfirst positioned within proximity of the defect, and the device was thenactuated by the user to deploy the extendable members. The tissue onopposing sides of the opening were engaged by the tissue engagementmechanisms (sharpened tissue hooks in this example), and then the devicewas actuatingly retracted by the user to pull the engaged tissuelocations toward the central axis of the device, thereby approximatingthe tissue near the distal end of the device. The user then actuated thefastener deployment mechanism to deform and eject the box-type staple,as described previously.

In other embodiments of the present invention, it may be advantageous toemploy various other alternative configurations for the tissueengagement mechanisms, depending on the nature of the tissue to beengaged and purpose of the interventional procedure. For example, asshown in FIG. 8, in the case where there is a hole-type defect 805present in a gastrointestinal tissue layer 810, and it is desired tosafely close and more permanently repair said hole-type defect using anentirely endoscopic approach (i.e. from inside the gastrointestinallumen), it may be desirable to reverse the direction of the sharpenedtissue hooks. Such a configuration is illustrated in FIG. 8A, wheredistal tool assembly 815 incorporates sharpened tissue hooks 820 thatare oriented pointing away from the central axis of the device. Asshown, this allows the user to position the device directly overhole-type defect 805, and the extendable members can therefore bedeployed inside hole-type defect 805, either partially or completelypenetrating through gastrointestinal tissue layer 810. In this manner,sharpened tissue hooks 820 are able to engage tissue located on theopposite (i.e. outside the gastrointestinal lumen) tissue surface. Theoutside surface of gastrointestinal tissue layer is covered by serosaltissue layer 822 that is thin, yet extremely tough, and thereforeprovides for a much stronger and more secure fastener placement comparedto deploying the fastener into the interior mucosal tissue surface 824.The serosal tissue layer is also known to heal itself rapidly and itwill form a strong bond to itself within 14 days after the intervention,resulting in a defect-repair that is more durable and permanent thatthat provided by a fastener alone. As shown in FIG. 8B, the use ofoutward facing sharpened tissue hooks 820 allows the serosal tissuesurfaces on opposing sides of the hole-type defect, as shown at 826 and828, respectively, to be brought into intimate contact when the tissueis approximated by the actuated retraction of the extendable members.The subsequent deployment of box-type staple 830 into the issue thenprovides secure fastening of the intimate serosa-to-serosa contact thatis established during tissue approximation.

In embodiments where the device is designed to engage tissue on theopposite side of the target tissue layer from the direction of approachby the device, as in the situation described above with regard to FIG.8, other necessary modifications may be incorporated to allow theapproximated tissue to be readily and controllably released from thedistal end of the device, without interference, after the fastener hasbeen placed. For example, it may be desirable that, prior to fastenerdeployment, the approximated tissue first be pulled along the length of,or into, the longitudinal tube assembly, proximally to a position beyondthe position where the fastener deployment occurs. This configurationallows the tissue engagement mechanisms to release the tissue uponslight distal actuation of the moveable arms after fastener deployment.In another embodiment, the sharpened tissue hooks may be produced from ahighly elastic, flexible material, such as spring steel, superelasticalloy (e.g. NiTi) or the like. In this case, the tissue hooks may bedesigned having an elastic strength limit such that during the initialactuated retraction of the moveable arms, the hooks are strong enough toretain their shape, remaining in the configuration suitable for tissueengagement and approximation, but after the fastener is deployed, theuser can actuatingly increase the proximal tension on the moveable armsto a value sufficient to elastically deform the tissue hooks, which thenat least partially straighten and pull out of the tissue to release theengagement, followed by recovery of their shape to the proper tissueengagement configuration when the tension is removed. In yet anotherembodiment, the distal tool assembly may be configured having one ormore vacuum ports in communication with a remote vacuum source, suchthat after tissue approximation, the vacuum can applied and used to holdthe engaged tissue locations in the approximated configuration, whilethe tissue hooks are released from the tissue and repositioned out ofthe way, so as not to interfere with subsequent fastener deployment.After the fastener is deployed to securely maintain the tissue in theapproximated configuration, the vacuum can be removed and the tissuereleased from the distal end of the device.

According to another embodiment of the present invention, FIG. 9 showsclose up details of the distal end of system 900, along with a targettissue layer 950 having a hole-type defect 960 therein, in order toillustrate the operational sequence of the device, as well as details ofthe fastener design and delivery mechanism. In FIG. 9A, the device isshown in the pre-deployed configuration prior to contacting tissue, i.e.moveable arms 918 are retracted into longitudinal tube assembly 910.Fasteners 902 to be deployed into tissue are positioned near the distalend of the device. In this example, fasteners 902 are crown-shaped, i.e.they have a cylindrical base 904 and two or more circumferentiallyarranged legs 906 that extend distally, with sharpened tips 908 designedfor penetrating tissue. Fasteners 902 are pre-loaded onto, and designedto slide along, guide shaft 912, forming a magazine within longitudinaltube assembly 910. When positioned near the distal end of the device,fasteners 902 may optionally be covered by an outer tube (not shown) inorder to protect the trocar seal during device insertion and to preventaccidental damage to tissue. During post-firing retraction of onefastener, the fasteners within the magazine are advanced distally,one-by-one, into the pre-fired position, by a spring-loaded mechanism(not shown) positioned inside longitudinal tube assembly 910, toward theproximal end of the fastener magazine. Fasteners 902 may be rigid,deformable and combinations thereof. In one embodiment, fasteners 902are produced from highly elastic material (e.g. spring steel,superelastic alloy such as NiTi, or the like) and are designed toreconfigure in a self actuating manner from a first configuration (e.g.the loaded and pre-fired configuration, as shown) to a secondconfiguration when deployed (e.g. having legs that at least partiallychange shape to close, grab, grasp, or otherwise more effectively engagethe target tissue). Optionally, the legs 906 and/or sharpened tips 908of fasteners 902 are further configured with at least one or morefeatures positioned on their tissue contacting surfaces that aredesigned to prevent the fasteners from slipping, migrating, coming outor otherwise moving after being deployed into tissue. Examples of suchfeatures, well known in the art, include barbs, teeth, serrations, andhooks, among others.

In FIG. 9B, the proximal handle assembly (not shown) has previously beenactuated by the user, thereby causing moveable arms 918 to move to thedeployed configuration, extending out of and away from the distal end ofthe device, and being positioned appropriately with tissue hooks 928located over top of defect 960 in tissue layer 950 in order tosubsequently engage tissue. In FIG. 9C, the tissue has been engaged onopposite sides of the defect 960, and the user has reverse actuatedproximal handle assembly (not shown) in order to retract moveable arms918, thereby causing the engaged tissue locations to move toward oneanother and the tissue to be approximated near the distal end of thedevice. Fastener deployment tube 914 is configured as a movable outerportion of longitudinal tube assembly 910 that is designed to slide overguide shaft 912 and push against the proximal edge of crown 904 onfastener 902 when the fastener deployment knob (located at proximalhandle assembly, not shown) is actuated by the user by pushing distally.As shown in FIG. 9C, this provides a distally directed longitudinalforce 915 that pushes fastener 902 off the end of guide shaft 912,thereby penetrating the tissue. As shown in FIG. 9D, after disengagingfrom the tissue, moveable arms 918 are retracted back to thepre-deployed configuration, and a deployed fastener 920 is implanted inthe tissue 950 and thereby securely holds the tissue in the approximatedconfiguration. As further shown in FIG. 9D, the next pre-loaded fastener902 is automatically moved into the pre-fired configuration, ready fordeployment as the above procedure may be optionally repeated.

Alternative novel embodiments for systems that incorporate a fastenerand fastener delivery mechanism into the tissue approximation devices ofthe present invention will now be described. In these embodiments, thetissue approximation device is configured such that at least a portionof at least one of the moveable members, typically a portion involvingat least the arm tip having associated tissue engagement means, breakoffs, disengages or is otherwise actuatingly and controllably releasedto remain behind, engaged with and implanted within the target tissuethat has been approximated, thereby acting as the securing means. This“break-away” fastener concept greatly simplifies the overall deviceconstruction, especially for use in circumstances when only a singlefastener may be needed, or when manual fastener reloading is acceptable,for example in the hole-type defect closure application. This allows fora smaller device footprint, eliminating the need for incorporatingseparate individual pre-loaded fasteners and associated multi-firefastener delivery mechanisms within the device. It also completelyavoids any difficulties associated with releasing the engaged tissuefrom the distal end of the device after fastener placement, obviatingthe needs for special design considerations when engaging tissue on theopposite side of the target tissue layer from the direction by which thedevice approaches.

According to one embodiment of the present invention, FIG. 10 showsclose up details of the distal end of a tissue approximation andfastening system 1000, along with a target tissue layer 1050 having ahole-type defect 1060 therein. In FIG. 10A, the device is shown in thepre-deployed configuration prior to contacting tissue, i.e. the moveablearms 1005 are retracted into longitudinal tube assembly 1010. Note inthis example that tissue hooks 1015 are configured to face outwardrather than inward in order to allow the tissue surface on the oppositeside from which the device approaches to be engaged, as described shownpreviously (i.e. in FIG. 8). Positioned and releaseably held in place atthe distal end of longitudinal tube assembly 1010 is retainer ring 1020,through which moveable arms 1005 slidably pass when actuated.

As shown in FIG. 10B, prior to actuating the tissue approximationfunction of the device, the distal end of longitudinal tube assembly1010 is first passed at least part way into, and in some casescompletely through, tissue layer 1050 via the opening in the tissuelayer 1050 caused by hole-type defect 1060. As described previously,this example is similar to the situation a surgeon would encounter whenfinding it necessary to endoscopically close a hole though thegastrointestinal lumen created by the surgeon in order to access theabdominal cavity during a natural orifice transluminal endoscopicsurgery (NOTES) procedure. By first passing the distal end of the devicethrough the defect, this places the outward facing tissue hooks 1015 onthe opposite side of the tissue layer from the direction of approach ofthe device, allowing the distal or exterior serosal tissue surface 1065to be engaged and approximated rather than the proximal or interiormucosal tissue surface 1070.

As seen in FIG. 10C, moveable arms 1005 are actuated and deployed by theuser, positioning tissue hooks 1015 appropriately for engaging thetissue layer on its distal surface 1065 beyond the edges of thehole-type defect 1060. In this example (as well as the example of FIG.8), where the goal is to close an access hole created through thegastrointestinal lumen during a NOTES procedure, the device may beinserted into the patient's gastrointestinal tract via a transoral ortransanal endoscopic approach, and when passed through the defect anddeployed, tissue hooks 1015 are positioned appropriately to engage themore robust and secure serosal tissue on the external surface of thegastrointestinal lumen. In this manner, when moveable arms 1005 areactuatingly retracted by the user, the engaged tissue on the distalsurface of tissue layer 1050 is pulled proximally toward the distal endof the device, back through the tissue opening at defect 1060,effectively everting the tissue and bringing the exterior tissue surfaceinto intimate contact with itself along the axis passing through thedefect. In the case of the tissue layer being a gastrointestinal tissuelayer, the external (extraluminal) tissue surface is covered withserosal tissue, which when brought into intimate contact as describedabove will heal by adhering to itself, producing a strong and durableserosa-to-serosa bond within 14 days after surgery, and therebyproviding additional strength to the defect closure provided by system1000, as described previously.

As further shown in FIG. 10C, moveable arms 1005 are configured havingreduced cross section 1025 positioned proximally relative to tissuehooks 1015. The purpose of reduced cross section 1025 is to provide apre-determined location where moveable arms 1005 will intentionallyfracture when the tensile force generated within moveable arms 1005during actuated retraction by the user (from within the proximal handleassembly, not shown) exceeds a designed value. Retainer ring 1020 isconfigured having surface features (not shown) on at least one internalsurface of the openings through which moveable arms 1005 pass. Saidsurface features are designed to interact with opposing surface features(not shown) present on a slidably contacting surface of moveable arms1005, distal to reduced cross section 1025. The interacting surfacefeatures on the inside of retainer ring 1025 and the distal portion ofmoveable arms 1005 are designed to be a one-way direction of travelmechanism. To describe this further, there is easy (low forcerequirement) sliding of moveable arms 1005 through the smooth slots inretainer ring 1020 when initially moving in the distal direction (i.e.during initial deployment of moveable arms 1005), but during theproximal motion of retraction, moveable arms 1005 are re-positioned(e.g. by a cam, latch, pivot or other similar mechanism, not shown) toslide inside non-smooth slots. In this manner, once moved proximallybeyond a certain distance during retraction, a mechanism is engaged suchthat further distal motion is prevented and further proximal motion isincrementally controlled, similar to a ratchet. This mechanism issimilar to the well known one-way direction of travel mechanisms used,for example, on plastic wire ties, which can be tightened by pulling inone direction, but cannot be loosened or removed by pulling in theopposite direction. Other mechanisms that achieve similar functionalresults are well known to those skilled in the art and may be used forthe present purposes within the scope of the present invention,including various combinations of linear gears, levers, cams, springsand the like.

As illustrated in FIG. 10D, as moveable arms 1005 are retracted suchthat reduced cross section 1025 moves proximally of retainer ring 1020,the above described one-way direction of travel mechanism becomesactively engaged and causes a gradual compression and tightening of thetissue engaged by tissue hooks 1015 against the distal surface retainerring 1020. Upon further retraction and tightening, the tensile forceswithin moveable arms 1005 are gradually increased until each of moveablearms 1005 fractures at the pre-determined positions defined by reducedcross section 1025. The fractured-off distal end of moveable arms 1005,including tissue hooks 1015 with tissue remaining engaged thereto, arethen fixedly interconnected with retainer ring 1020, thereby becoming aunitary fastener assembly 1030. By actuating a mechanism in the proximalhandle assembly (not shown) retainer ring 1020 is then releasablydisengaged from pins 1028 positioned at the distal end of longitudinaltube assembly 1010, leaving fastener assembly 1030 implanted in thetissue as the securing means to hold the tissue in the approximatedconfiguration, thereby closing hole-type defect 1060 in tissue layer1050.

Another embodiment of a tissue approximation and fastening systemaccording to the present invention is shown in FIG. 11. System 1100 maybe configured for use in laparoscopic, endoscopic or open procedures andconsists of proximal handle assembly 1105, longitudinal tube assembly1110 and distal tool assembly 1115. Distal tool assembly 1115, whoseoperation shall be explained in detail below, is shown in thepre-deployed configuration and includes distal tissue hook 1120 andproximal tissue hook 1125. Proximal tissue hook 1125 is releasablyattached to the distal end of longitudinal tube assembly 1110, whereasdistal tissue hook 1120 is positioned at the end of a moveable shaft1122 (see below, FIG. 12) which is operably connected to proximal handleassembly 1105 via longitudinal tube assembly 1110. Proximal handleassembly is further configured having deployment knob 1130 and trigger1135, whose functions will be described below.

FIG. 12 shows close up details of the distal end of system 1100, alongwith a target tissue layer 1250 in which the surgeon may be intending tocreate one or more tissue folds and secure said one or more folds toproduce one or more plications, as may be desirable for example, in aprocedure that reduces the volume of the gastrointestinal lumen as asurgical treatment for obesity. During initial actuated deployment,distal tissue hook 1120 is extended longitudinally and distally awayfrom the end of the device when the user pushes deployment knob 1130located on proximal handle assembly 1105. This causes distal tissue hook1120 and proximal tissue hook 1125 to be spaced apart a user controlleddistance and positioned appropriately for subsequent tissue engagement.The user is then able to engage tissue at each of two separately spacedapart locations by bringing the distal end of system 1100 into contactwith target tissue layer 1250, where the distal longitudinal axis of thedevice 1205 is held substantially parallel to the surface of saidtissue, as shown in FIG. 12A. While this particular embodiment isdesigned such that the distal longitudinal axis of the device 1205 mustapproach the tissue substantially parallel to its surface, as shown, itshould be recognized that articulation and rotation mechanismssubstantially similar to what was described previously (see device 100and FIG. 5) can readily be incorporated into system 1100, if desired. Inthis manner, for example, the device may easily be used withconventional laparoscopic abdominal wall port placements and still allowthe necessary parallel orientation relationship between the distal endof the device and the target tissue to be established for performing thetissue approximation and fastening.

It should be obvious to those skilled in the art that the user mayoptionally engage the two tissue locations simultaneously, oralternatively, either of the proximal tissue hook 1125 or distal tissuehook 1120 may be used to initially engage the tissue at a firstlocation, followed by separate engaging of tissue at a second locationusing other tissue hook. Irrespective of the order of tissue engagement,fastener deployment proceeds as described below. The operational choiceregarding the order of tissue engagement may therefore be made by theuser, largely as a matter of convenience, based on the procedure, tissuetype, patient's specific anatomy, etc.

As further illustrated in FIG. 12A, once tissue has been engaged at eachof the two separately spaced apart locations, the user actuatesretraction of moveable shaft 1122 by squeezing trigger 1135 located onproximal handle assembly 1105. Trigger 1135 is operably connected to asuitable one-way ratchet-type mechanism (not shown) that is configuredinside proximal handle assembly 1105. Said one-way ratchet-typemechanism is designed and configured to generate a tensile force 1210that incrementally and forceably pulls moveable shaft 1122 in theproximal direction, while preventing its distal motion. Such mechanisms,similar to those used in caulking guns and the like, are very simple andwell known in the art, typically being constructed using a linear gearand one or more levers, cams, springs, and the like. The continuedactuated retraction of moveable shaft 1122 by the operator draws distaltissue hook 1120, with the tissue engaged thereto, toward proximaltissue hook 1125, causing the engaged tissue locations to beapproximated near the distal end of the device. In one exemplary usageof this device, a fold 1260 may be created in the tissue, as shown inFIG. 12B. To improve safety and provide the surgeon flexibility toensure the tissue approximation is proceeding in the desired manner,before delivering the fastening means, system 1100 may optionally beconfigured with a release mechanism (not shown) that allows the user toquickly and easily disengage the one-way ratchet mechanism, therebyreleasing moveable shaft and allowing it to again be moved distally. Inthis manner the surgeon may disengage from tissue or reposition thedevice before re-initiating tissue approximation.

In terms of deploying a fastener assembly to securely hold the tissue inthe approximated configuration, distal tool assembly 1115 of system 1100is constructed and operates in a substantially similar manner to thatdescribed previously for system 1000 (FIG. 10). Accordingly, shown inFIG. 12A and FIG. 12B is reduced cross section 1220 on moveable shaft1122, located at a pre-determined position proximal to distal tissuehook 1120. The purpose of reduced cross section 1220 is to provide aspecified location where moveable shaft 1122 will intentionally fracturewhen the tensile force generated within moveable shaft 1122 duringactuated retraction by the user exceeds a designed value.

In this embodiment, the pre-deployed fastener assembly is initiallyfixedly interconnected with proximal tissue hook 1125 (which isreleasably attached to the distal end of longitudinal tube assembly1110), consisting of proximal guide 1222, distal guide 1224 and rail1226 positioned therebetween. Moveable shaft 1122 slides inside theproximal and distal guides such that there is created a sliding contactinterface between rail 1226 and moveable shaft 1122. Interacting surfacefeatures (e.g. directional teeth, ridges, bumps, etc.) are present onthe inside contact surface of rail 1226, and also on the inside contactsurface of moveable shaft 1122 in between proximal tissue hook 1125 andreduced cross section 1220. These interacting surface features aredesigned to provide a one-way direction of travel mechanism, similar tothat used in plastic wire ties, well known in the art, and previouslydescribed previously in FIG. 10 with regard to system 1000. In thismanner, when the user actuates retraction of sliding shaft 1122 usingtrigger 1135, after the reduced cross section of moveable shaft 1122moves proximally beyond distal guide 1224, the one-way direction oftravel mechanism becomes actively engaged, resulting in a mating of thefastener assembly components (i.e. proximal tissue hook 1125, proximalguide 1222, distal guide 1224, rail 1226, and the broken off portion ofmoveable shaft 1122 with distal tissue hook 1120 attached thereto).Further actuated retraction by the user results in approximation of theengaged tissue locations and gradual compressive tightening as distaltissue hook 1120 and proximal tissue hook 1125 are ratcheted toward oneanother.

Continued retraction by the user gradually increases the tensile forcewithin moveable shaft 1122 until reduced cross section 1220 fractures atthe designed force value. As shown in FIG. 12C, proximal tissue hook1125 is then releasably disengaged from the distal end of longitudinaltube assembly 1110 leaving the deployed unitary fastener assembly 1230implanted in the tissue as the securing means to hold the tissue in theapproximated configuration, in this example producing plication 1270within target tissue layer 1250.

System 1100 as illustrated is a single loading unit device, designed toapproximate tissue and deploy a single fastener assembly as describedabove. Accordingly, this device may be withdrawn from the patient,reloaded, then re-inserted and positioned appropriately to allow thesurgeon to repeat the aforementioned operational steps any number oftimes, thereby extending the tissue approximation and fasteningcapabilities beyond a single firing. This may be useful, for example, inorder to produce a longer and more securely fastened plication, asillustrated in FIG. 12D. While the embodiment of system 1100 shown inFIG. 11 and FIG. 12 is a single loading unit device, various engineeringdesign and construction modifications may be made using methods wellknown in the art in order to produce multi-fire device embodimentsoperating on substantially similar design principles; such embodimentsare considered obvious extensions of the novel technology describedherein and are therefore considered within the scope of the presentinvention.

In certain other embodiments of the present invention, it is possible toconfigure the devices such that the distal tool assembly provides amulti-functional mechanism that is designed to both approximate andfasten tissue. This can potentially further reduce the complexity andcost of the device. For example, in contrast to the distal tool assemblydescribed in FIG. 7, which provides separate actuatingly operablemechanisms for approximating and fastening the tissue, the alternativeembodiment described below uses a partially deployed fastener to serveas the extendable members of the present invention that are used toengage tissue. In this embodiment, with the fastener positioned in thepartially deployed configuration, according to the methods of thepresent invention, tissue may be engaged at one location, the device maythen be repositioned to engaged tissue at a second location, moving thefirst engaged tissue location toward the second engaged tissue locationin order to approximate the tissues near the distal end of the device,and then the fastener may be fully deployed and released from the deviceto secure the tissue in the approximated configuration.

One such embodiment is illustrated in FIG. 13, which shows an overviewof a laparoscopic device 1300 having handle assembly 1305, longitudinaltube assembly 1310 and distal tool assembly 1315. Distal tool assembly1315 is configured having at least one tissue engaging fastener 1320that is capable of being releasably held in a partially-deployedconfiguration, during which time it is used to carry out the tissueapproximation functions of the device. In the partially-deployedconfiguration at least one or more tissue penetrating members offastener 1320 that are capable of engaging tissue are sufficientlyexposed beyond the distal end of the device so as to allow tissue to beengaged at two or more locations. Further details of this deviceconfiguration and its use to approximate and fasten tissue will bedescribed below.

An exemplary tissue fastener of the present invention is a deformablebox-type staple 1400 shown in the pre-deployed configuration in FIG. 14Aand in the deployed configuration in FIG. 14B. This type of fastener iscompatible with various embodiments of the present invention, such asthe embodiments described in FIG. 7 and/or FIG. 13. In the pre-deployedconfiguration, box-type staple 1400 consists of deformable proximalmember 1405 and two or more tissue penetrating members, such as tissuepenetrating members 1410 and 1415. Each tissue penetrating member isfurther configured having a tissue engagement mechanism configured inproximity to its distal end. In the example shown, the tissue engagementmechanism consists of sharpened tip 1420 combined with inward pointingbarb 1425. Sharpened tip 1420 promotes penetration of tissue with a lowforce requirement, whereas after tissue engagement, inward pointing barb1425 prevents the tissue from accidentally slipping or disengaging fromthe tissue penetrating member during subsequent tissue manipulation.During fastener deployment, after tissue has been approximated by thedevice, proximal member 1405 is deformably reconfigured by the distaltool assembly (e.g. by operator actuation of the handle assembly, notshown) such that tissue penetrating members 1410 and 1415 first movetoward and then slide past one another. In the final deployedconfiguration tissue penetrating members 1410 and 1415 overlap, as shownin FIG. 14B, such that box-type staple 1400 assumes a continuous, closedloop profile wherein no sharpened tips are exposed that may result inaccidental tissue damage or chronic irritation by the implant. Deployedbox-type staple 1400 is preferably reconfigured into an unique shape,such as, for example, the polygonal shape illustrated in FIG. 14B. Inthis example, the smallest dimension in staple width 1430 occurs nearits proximal end, at the position along the deformable proximal memberwhere the fastener was releasably held by device 1300 in itspre-deployed and/or partially deployed configuration. In contrast, thelargest dimension in staple width 1435 occurs at the distal end nearwhere tissue penetrating members 1410 and 1415 overlap. Note also thatin the deployed configuration, box-type staple 1400 has an overalllength dimension (i.e. the distance dimension along the longitudinalaxis of the device) 1440 that exceeds its maximum width dimension 1435,meaning the staple aspect ratio is configured such that it is relativelylonger along a direction parallel to the longitudinal axis of thedevice. This exemplary staple shape and aspect ratio is notablydifferent from prior art box-type staples, and is considered a uniquefeature of one fastener embodiment of the present invention. While notobvious, it has been found through experimentation that this polygonaldeployed shape of box-type staple represents an optimal tradeoff betweenseveral competing needs. For example, it is desirable to providesufficiently long tissue penetrating members to promote positive tissueengagement while in the pre-deployed and/or partially deployedconfiguration. At the same time, it is also desirable to provide a highdegree of compression to the tissue enclosed within the staple and tominimize the widest staple dimension 1435 so as to prevent the tissuesinside the staple from pulling very far apart under tension. It is yetfurther desirable to avoid exposure of sharp tips in the final deployedconfiguration. Note that, due to the orientation of the plane definingthe interfacial contact area between the two approximated tissuesurfaces relative to the orientation of the staple during deployment, inthe deployed configuration this unique staple shape and aspect ratioprovides for direct compression across a larger interfacial contact areathan is possible with prior art box-type staples having a B-shape,D-shape, etc. These are significant advantages of this uniquepolygonal-shaped deployed box-type staple when used in conjunction withthe tissue approximation and fastening devices of the present invention.

Referring again to FIG. 13, and assuming an exemplary fastener such asthat illustrated in FIG. 14 is utilized, FIG. 15 shows a close-up viewof the distal end of a device according to one embodiment of the presentinvention. In this example, distal tool assembly 1505 is configured atthe distal end of a longitudinal tube assembly. One or more fastenersmay be initially provided in a pre-deployed configuration, such aspre-deployed box-type staples 1515, that are slidably held, temporarilystored or otherwise moveably positioned within outer tube assembly 1510.Upon initial actuation by the operator (e.g. remotely from the handleassembly, not shown) the fastener may be moved (e.g. by a spring loadedmechanism) from its initial pre-deployed configuration to a partiallydeployed configuration, such as partially deployed box-type staple 1520.In the partially deployed configuration, box-type staple 1520 is heldfirmly, yet releasably in place by frictional forces between stationaryanvil 1525 and movable staple former 1530. In some configurations (notshown) it may be desirable to incorporate one or more features such asnotches, grooves, indentations, or the like, into the deformableproximal member of box-type staple 1520 to prevent slippage orinadvertent premature release of the staple while held in the partiallydeployed configuration. Moveable staple former 1530 may be configured inoperable communication with various springs, gears, ratchets or othersimilar mechanisms known in the art for reversing its direction oftravel during staple advancement and for transmitting an appropriatelinear mechanical force needed to hold the staple securely againststationary anvil 1525. Note in the partially deployed configuration thetissue penetrating members 1535 are exposed beyond the distal end of thedevice. In this manner, exposed tissue penetrating members 1535, havingdistal tissue engagement mechanisms attached thereto (as described inFIG. 14), may be used for engaging and approximating tissue, asdescribed in FIG. 16 below. An advantage of this device configuration isthat, beyond the staple actuation mechanisms, no additional members,moveable components, mechanisms, etc. are needed to engage andapproximate tissue. After tissue approximation, the operator actuatesthe device, moving staple former 1530 distally relative to stationaryanvil 1525. This deforms the box-type staple, reconfiguring it into itsfully deployed polygonal shape and thereby compresses the tissuesenclosed between tissue penetrating members. Finally, the fully deployedbox-type staple is released from the distal end of the device and leftbehind implanted in the tissue to secure the tissue in the approximatedconfiguration. Note that during actuated staple forming it is thedimensions and shapes of the mating surfaces, as well as the appliedforces between stationary anvil 1525 and moveable staple former 1530that may be optimized to control the final deployed polygonal stapleconfiguration, preferably as described in FIG. 14.

According to the embodiments described above in FIG. 13-FIG. 15, duringuse, the sequence of steps for approximating and fastening tissue forthe exemplary purpose of creating an invaginated tissue fold isillustrated in FIG. 16. As shown in FIG. 16A, after insertion of thedevice into the patient's body distal tool assembly 1602 is firstpositioned above and in proximity to the target tissue surface 1604. Thedevice is then actuated and a box-type staple is moved from its initialpre-deployed configuration 1606 to the partially deployed configuration1608, in which tissue penetrating members 1610 and 1612 are moved intoan exposed position. As shown in FIG. 16B, the position of the devicemay then be manipulated by the operator (e.g. by any combination ofmotions such as pushing, pulling, rotating, dragging, pivoting, and thelike, as shown at 1614) to allow a first tissue engagement mechanism1616, configured as part of a first tissue penetrating member 1610, toengage tissue at a first target location 1618 on the tissue surface. Asshown in FIG. 16C, the distal end of the device, having the first targettissue 1618 attached thereto, is then moved as shown at 1620, andrepositioned to be in proximity to a second target tissue location 1622on the tissue surface. The device is then again manipulated by theoperator as shown at 1624 in order to allow a second tissue engagementmechanism 1626, configured as part of second tissue penetrating member1612, to engage tissue at the second target location 1622 on the tissuesurface. In this manner, tissue has been operatively engaged at twoseparately spaced locations 1618 and 1622 on the tissue surface and theengaged tissues have been moved toward one another and approximated nearthe distal end of the device, as illustrated in FIG. 16D. After theoperator again actuates the device, as shown in FIG. 16E, the box-typestaple is deformably reconfigured from its partially deployedconfiguration 1608 to its fully deployed configuration 1630, after whichit is released from the device and left implanted in the tissue tosecurely hold the tissue in the approximated configuration. In theexample shown, as a result of using the devices of the present inventionaccording to the methods of the present invention in order toapproximate and fasten tissue, an invaginated tissue fold 1635 has beenproduced. Tissue fold 1635 projects away from the distal end of thedevice and the tissue engagement locations 1618 and 1622 are held insubstantially intimate contact inside the tissue fold.

We claim:
 1. A method for approximating and fastening tissue comprisingsequentially: positioning a device having a distal tool assemblyincorporating at least one tissue fastener having two or more tissuepenetrating members in a pre-deployed configuration in proximity totarget tissue surface; moving the at least one tissue fastener from itspre-deployed position within the distal tool assembly to a partiallydeployed configuration in which at least two tissue penetrating membersof the tissue fastener are exposed beyond the distal end of the device;engaging tissue at a first location with at least one penetrating memberof the at least one tissue fastener; repositioning the engaged tissueand the at least one tissue penetrating member to approximate tissue atthe first location toward a second location and forming an invaginatedtissue fold projecting away from the distal tool assembly and the firstand second location; engaging tissue at the second location with anotherof the tissue penetrating members; and deformably reconfiguring thetissue fastener from its partially deployed configuration to its fullydeployed configuration and releasing the tissue fastener from the toolassembly to securely hold the first and second tissue locations in theapproximated configuration, thereby securing the invaginated tissuefold.
 2. The method of claim 1, wherein the tissue penetrating membershave barbs.
 3. The method of claim 1, wherein the at least one tissuefastener is a staple and wherein deformably reconfiguring the at leastone staple reconfigures the staple such that the tissue penetratingmembers move toward and then move past one another.
 4. The method ofclaim 1, wherein deformably reconfiguring the at least one tissuefastener deformably reconfigures the tissue fastener in apolygonal-shaped loop.
 5. The method of claim 1, wherein deformablyreconfiguring the at least one tissue fastener deformably reconfiguresthe tissue fastener such that a smallest deployed dimension of thetissue fastener occurs near its proximal end and a largest deployeddimension occurs at a distal end near where tissue penetrating membersoverlap.
 6. The method of claim 1, wherein deformably reconfiguring theat least one tissue fastener deformably reconfigures the tissue fastenersuch that a overall length dimension in the direction of tissuepenetration exceeds a maximum width dimension.
 7. The method of claim 1,wherein tissue is engaged at first and second spaced apart tissueengagement locations sequentially.
 8. The method of claim 1,additionally comprising performing successive tissue engagement,approximation and securing steps.
 9. The method of claim 1, performedwithout removing the device from its position in proximity to the tissuesurface.
 10. method of claim 1, wherein repositioning the engaged tissueto approximate the first and second target tissue locations is achievedby an operator dragging the first engaged tissue location to the secondlocation, thereby approximating the engaged tissue locations.
 11. Themethod of claim 1, wherein the two or more tissue penetrating membersare configured as opposing legs of a deformable staple.
 12. The methodof claim 1, wherein the tissue penetrating members have sharpened tips.13. The method of claim 1, wherein engaging tissue at the first locationis achieved by manipulating the position of the distal tool assembly.14. The method of claim 1, wherein repositioning engaged tissue isachieved by manipulating the position of the distal tool assembly usingpushing, pulling, rotating, dragging or pivoting motions.
 15. The methodof claim 1, wherein the tissue fastener is a box-type staple.
 16. Themethod of claim 1, wherein the at least one tissue fastener is adeformable staple and the tissue penetrating members are opposing legsof the deformable staple.
 17. The method of claim 1, wherein the firstand second tissue engagement locations are spaced apart further than thedistance between the tissue penetrating members.